1. Field of the Invention
The present invention relates to a communication device and a method used in a wireless communication system, and more particularly, to a communication device and a method of handling a radio access technology tight interworking of two cellular systems.
2. Description of the Prior Art
A long-term evolution (LTE) advanced (LTE-A) includes a carrier aggregation (CA), a Dual Connectivity (DC), a LTE transmission over an unlicensed spectrum (e.g., LTE-unlicensed (LTE-U) or licensed-assisted access (LAA)).